Given a rectangle with length equal to 8cm and width equal to (3x + 5) cm, which expression below represents the area of the rectangle. Select one:

a. 3x + 13

b. 24x - 40

c. 24x + 5

d. 24x + 40

d

Step-by-step explanation:

area=l×w

=8(3x+5)

24x+40

the solution of the equation is 2.23 ⇒ answer b

step-by-step explanation:

* lets revise the meaning of exponential function

- the form of the exponential function is y = ab^x, where a ≠ 0, b > 0 ,  

  b ≠ 1, and x is any real number

- it has a constant base b

- it has a variable exponent x

- to solve an exponential equation, take the log or ln of both sides,  

  and solve for the variable

* lets solve the problem

∵

- the base is 7 and the exponent is x

- insert ㏑ in both sides

∴

- use the rule

∴ x ㏑(7) = ㏑(77)

- to find x divide both sides by ㏑(7)

∴

* the solution of the equation is 2.23 to the nearest 2 decimal places